By the _Treaty of Adrianople_, September 14, 1829, Russian ascendancy in the principalities of the Danube was permanently assured, and the whole of the Caucasus was converted into Russian territory. The Straits were declared free and open to merchant ships of all Powers. The Turkish Government gave its adhesion to the Treaty of London regulating the Greek frontier. Remarks: Russia’s hold over Turkey was greatly strengthened, but the establishment of an absolutely independent kingdom in Greece was finally secured. WAR BETWEEN HOLLAND AND BELGIUM 1830–1839 Belligerents: Holland. Belgium, France, Great Britain. Cause: The Kingdom of the Netherlands was set up by the Congress of Vienna in 1815, but from the first there was discord between the two states of the kingdom. King William was a Dutchman and a Protestant. Holland, although the smaller of the two states, had a permanent majority in the Chamber. Public offices and appointments were filled by Dutchmen. The hatred of Dutch rule grew, and with it a desire for separation. Occasion: The success of the French Revolution of 1830 led to an outbreak in Brussels, and Belgian insurgents fought against the Dutch soldiers. The Powers met in London, and Belgium was declared a separate kingdom. Leopold of Saxe-Coburg was offered the crown and entered Brussels as King of the Belgians on June 21, 1831; at the same time the Dutch prepared for an invasion. Course of the War: On August 9, 1831, the Belgians were routed in an encounter with the Dutch, but on the intervention of the French army King William withdrew. The Conference in London drew up a treaty, but King William refused to come to terms and retained possession of Antwerp. In November a combined British and French fleet sailed for the coast of Holland, and a French army laid siege to Antwerp. The Dutch garrison capitulated on December 23, 1831, and the town was handed over to the Belgians and the French troops withdrew. Still the Dutch refused to yield and held two forts which enabled them to command the navigation of the Scheldt. Not till March 1838 did Holland signify her readiness to accept the treaty. Political Result: The Conference throughout had endeavoured to come to an agreement; Austria, Prussia, and Russia sympathized with Holland; but eventually the final _Treaty of London_ was signed on April 19, 1839. Luxemburg was divided, and also the district of Maestricht. The Scheldt was declared open to the commerce of both countries. The national debt was divided, and the five Powers guaranteed the independence and neutrality of Belgium. Remarks: As independent states the two countries lived side by side amicably. The neutrality of Belgium was reaffirmed in 1870 on the outbreak of the Franco-German War. Leopold was succeeded in 1865 by his son Leopold II, under whose sovereignty the Congo Free State was placed in 1885. King Albert succeeded his uncle in 1909. WAR IN PORTUGAL AND SPAIN 1830–1839